3(7х+5)=7(3х-2)+10х
21x+15=21x-14+10x 21x-21x-10x=-14-15 -10x=-29 *(-1) 10x=29 x=29/10 x=2,9
3*(7х+5)=7*(3х-2)+10х 21х+15=21х-14+10х 21х-21х-10х=-15-14 -10х=29 х=29/10 = 2 9/10